一、Xen的配置文件说明
Xen配置文件一般由选项（options）、变量(variables)、CPU、网络、PCI、HVM、计时器(timers)、驱动(drivers)、磁盘设备(disk devices)、动作(behavior)，以及图形及声音(Graphics and audio)几个段组成，分别用于定义不同类别的域属性或设备属性。
上面的配置文件中的各选项作用如下。
◇kernel：为当前域指定可用于DomU的内核文件；
◇ramdisk：与kernel指定的内核文件匹配使用的ramdisk映像文件，根据需要指定，此为可选项；
◇name：当前域的独有名称；每个域必须使用全局惟一的名称，否则将产生错误；
◇memory：当前域的可用物理内存空间大小，单位为MB，默认为128；
◇disk：当前域的所有可用磁盘设备列表，格式为disk = [ “disk1”, “disk2”, …]，每个
disk都有三个参数进行定义，格式为“backend-dev，front-dev，mode”；
backend-dev主要有两种类型，物理设备或虚拟磁盘映像文件，它们的格式分别为“phy:device”和“file:/path/to/file”；
frontend-dev定义其在DomU中的设备类型，一般为xvd[a-z];
mode则用于定义其访问权限，r为只读，w为读写；
◇vcpus：配置给当前域使用的虚拟CPU的个数；默认为1；
◇root：为当前域指定其根文件系统所在的设备，这个将作为内核参数在内核启动传递给内核；
◇extra：传递给内核的额外参数，其中selinux=0表示禁用selinux，init则用于指定init程序的路径；多个参数之间使用空格隔开；
◇on_reboot：执行xm reboot命令或在当前域内部执行重启操作时由Xen执行的动作；其常用的值为destroy和restart；
◇on_crash：当前域由于各种原因崩溃时由Xen执行的动作；其常用的值为destroy、restart和preserve，preserve可以保存系统崩溃前的状态信息以用于调试；
◇on_shutdown：执行xm shutdown命令或在当前域内部执行关机操作时由Xen执行的动作；
其它常用参数：
◇vif：定义当前域的可用虚拟网络接口列表，每个虚拟网络接口都可以使用“name=value”的格式定义其属性；也可在定义某接口时不指定任何属性，其所有属性将均由系统默认配置；例如：vif = ['ip = "192.168.1.19", bridge=xenbr0']
type：接口设备的类型，默认为netfront；
mac：MAC地址，默认为随机；
bridge：桥接到的物理设备，默认为Dom0中的第一个桥接设备；
ip：ip地址；
script：配置此接口的脚本文件，省略时将使用默认的配置脚本；
vifname：后端设备的设备名称，默认为vifD.N，其中D为当前域的ID，N为此网络接口的ID；
◇vfb：为当前域定义虚拟帧缓冲，其有许多可用属性，可以使用“name=value”的格式进行定义；
vnc或sdl：定义vnc的类型，vnc=1表示启动一个可由外部设备连接的vnc服务器，sdl=1则表示启用一个自有的vncviewer；两者可以同时使用；
vncdisplay：vnc显示号，默认为当前域的ID，当前域的VNC服务器将监听5900+此显示号的端口；
vnclisten：VNC服务器监听的地址，默认为127.0.0.1；
vncunused：如果此属性的值为非零值，则表示vncserver监听大于5900的第一个没被占用的端口；
vncpasswd：指定VNC服务器的认证密码；
display：用于域的自有vncviewer显示，默认为DISPLAY环境变量的值；
◇cpu：指定当前域应该在哪个物理CPU上启动，0表示第一颗CPU，1表示第二颗，依次类推；默认为-1，表示Xen可自行决定启动当前域的CPU；
◇cpus：指定当前域的VCPU可以在哪些物理CPU上运行，如cpus = ”3,5-8,^6”表示当前域的VCPU可以在3，5，7，8号CPU上运行；
◇bootloader：bootloader程序的路径；基于此bootloader，PV DomU的内核也可直接位于其文件系统上而非Dom0的文件系统；
更多的选项请参见xmdomain.cfg的手册页，或参考Xen官方wiki链接http://wiki.xen.org/wiki/XenConfigurationFileOptions中的详细解释。
二、确定硬件是否支持xen的需求
1、半虚拟化的支持
其实只要是64位x_86主机都能够支持半虚化需求，支持PAE,
[root@logicserver vm1]# cat /proc/cpuinfo | grep flags
flags : fpu de tsc msr pae mce cx8 apic sep mca cmov pat clflush acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl nonstop_tsc eagerfpu pni pclmulqdq monitor est ssse3 cx16 sse4_1 sse4_2 popcnt tsc_deadline_timer xsave hypervisor lahf_lm arat epb pln pts dtherm fsgsbase erms xsaveopt
flags : fpu de tsc msr pae mce cx8 apic sep mca cmov pat clflush acpi mmx fxsr sse sse2 ss ht syscall nx lm constant_tsc rep_good nopl nonstop_tsc eagerfpu pni pclmulqdq monitor est ssse3 cx16 sse4_1 sse4_2 popcnt tsc_deadline_timer xsave hypervisor lahf_lm arat epb pln pts dtherm fsgsbase erms xsaveopt
2、完全虚拟化的支持，目前X_86主机中，Intel提供的是VT技术，AMD提供的是SVM技术
什么都没显示，表示不支持
[
root@logicserver vm1]# egrep '{vt|svm}' /proc/cpuinfo
3、建立磁盘镜像文件，如果在生产环境上，建议不要使用dd来创建，使用qemu-img来创建，可以弹性调整磁盘空间大小
[root@logicserver ~]# qemu-img create -f raw /xen/vm2/centos6.img500G
[root@logicserver ~]# qemu-img info /xen/vm2/centos6.img
三、安装步聚
1、利用桥接模式
yum -y install bridge-utils
2、从centos6.5镜像文件，两个文件
[root@logicserver vmlinux]# ll
总用量 36644
-r--r--r--. 1 root root 33392971 9月 9 11:15 initrd.img
-r-xr-xr-x. 1 root root 4128368 9月 9 11:15 vmlinuz
[root@logicserver vmlinux]# pwd
/root/vmlinux
3、编辑/etc/xen/centos6的文件，centos6是从xmexample1复制而来例子配置文件，稍作修改
要改的选项有：
kernel = "/root/vmlinux/vmlinuz"
ramdisk="/root/vmlinux/initrd.img"
#ramdisk = "/boot/initrd.gz"
#root = "/dev/xvda ro" 注释
vif = [ 'bridge=br0' ]
on_reboot = 'destroy'
on_crash = 'destroy'
[root@logicserver xen]# vim centos6
# Kernel p_w_picpath file.
kernel = "/root/vmlinux/vmlinuz"
ramdisk="/root/vmlinux/initrd.img"
# Optional ramdisk.
#ramdisk = "/boot/initrd.gz"
# The domain build function. Default is 'linux'.
#builder='linux'
# Initial memory allocation (in megabytes) for the new domain.
#
# WARNING: Creating a domain with insufficient memory may cause out of
# memory errors. The domain needs enough memory to boot kernel
# and modules. Allocating less than 32MBs is not recommended.
memory = 1024
# A name for your domain. All domains must have different names.
name = "centos6"
# 128-bit UUID for the domain. The default behavior is to generate a new UUID
# on each call to 'xm create'.
#uuid = "06ed00fe-1162-4fc4-b5d8-11993ee4a8b9"
# List of which CPUS this domain is allowed to use, default Xen picks
#cpus = "" # leave to Xen to pick
#cpus = "0" # all vcpus run on CPU0
#cpus = "0-3,5,^1" # all vcpus run on cpus 0,2,3,5
#cpus = ["2", "3"] # VCPU0 runs on CPU2, VCPU1 runs on CPU3
# Number of Virtual CPUS to use, default is 1
#vcpus = 1
vcpus = 2
#----------------------------------------------------------------------------
# Define network interfaces.
# By default, no network interfaces are configured. You may have one created
# with sensible defaults using an empty vif clause:
#
# vif = [ '' ]
#
# or optionally override backend, bridge, ip, mac, script, type, or vifname:
#
# vif = [ 'mac=00:16:3e:00:00:11, bridge=xenbr0' ]
#
# or more than one interface may be configured:
#
# vif = [ '', 'bridge=xenbr1' ]
vif = [ 'bridge=br0' ]
#vif = [ '' ]
#----------------------------------------------------------------------------
# Define the disk devices you want the domain to have access to, and
# what you want them accessible as.
# Each disk entry is of the form phy:UNAME,DEV,MODE
# where UNAME is the device, DEV is the device name the domain will see,
# and MODE is r for read-only, w for read-write.
#disk = [ 'phy:hda1,hda1,w' ]
disk = [ 'file:/xen/vm2/centos6.img,xvda,w' ]
#----------------------------------------------------------------------------
# Define frame buffer device.
#
# By default, no frame buffer device is configured.
#
# To create one using the SDL backend and sensible defaults:
#
# vfb = [ 'sdl=1' ]
#
# This uses environment variables XAUTHORITY and DISPLAY. You
# can override that:
#
# vfb = [ 'sdl=1,xauthority=/home/bozo/.Xauthority,display=:1' ]
#
# To create one using the VNC backend and sensible defaults:
#
# vfb = [ 'vnc=1' ]
#
# The backend listens on 127.0.0.1 port 5900+N by default, where N is
# the domain ID. You can override both address and N:
#
# vfb = [ 'vnc=1,vnclisten=127.0.0.1,vncdisplay=1' ]
#
# Or you can bind the first unused port above 5900:
#
# vfb = [ 'vnc=1,vnclisten=0.0.0.0,vncunused=1' ]
#
# You can override the password:
#
# vfb = [ 'vnc=1,vncpasswd=MYPASSWD' ]
#
# Empty password disables authentication. Defaults to the vncpasswd
# configured in xend-config.sxp.
#----------------------------------------------------------------------------
# Set the kernel command line for the new domain.
# You only need to define the IP parameters and hostname if the domain's
# IP config doesn't, e.g. in ifcfg-eth0 or via DHCP.
# You can use 'extra' to set the runlevel and custom environment
# variables used by custom rc scripts (e.g. VMID=, usr= ).
# Set if you want dhcp to allocate the IP address.
#dhcp="dhcp"
# Set netmask.
#netmask=
# Set default gateway.
#gateway=
# Set the hostname.
#hostname= "vm%d" % vmid
# Set root device.
#root = "/dev/xvda ro"
# Root device for nfs.
#root = "/dev/nfs"
# The nfs server.
#nfs_server = '192.0.2.1'
# Root directory on the nfs server.
#nfs_root = '/full/path/to/root/directory'
# Sets runlevel 4.
#extra = "3 selinux=0 init=/sbin/init"
#----------------------------------------------------------------------------
# Configure the behaviour when a domain exits. There are three 'reasons'
# for a domain to stop: poweroff, reboot, and crash. For each of these you
# may specify:
#
# "destroy", meaning that the domain is cleaned up as normal;
# "restart", meaning that a new domain is started in place of the old
# one;
# "preserve", meaning that no clean-up is done until the domain is
# manually destroyed (using xm destroy, for example); or
# "rename-restart", meaning that the old domain is not cleaned up, but is
# renamed and a new domain started in its place.
#
# In the event a domain stops due to a crash, you have the additional options:
#
# "coredump-destroy", meaning dump the crashed domain's core and then destroy;
# "coredump-restart', meaning dump the crashed domain's core and the restart.
#
# The default is
#
# on_poweroff = 'destroy'
# on_reboot = 'restart'
# on_crash = 'restart'
#
# For backwards compatibility we also support the deprecated option restart
#
# restart = 'onreboot' means on_poweroff = 'destroy'
# on_reboot = 'restart'
# on_crash = 'destroy'
#
# restart = 'always' means on_poweroff = 'restart'
# on_reboot = 'restart'
# on_crash = 'restart'
#
# restart = 'never' means on_poweroff = 'destroy'
# on_reboot = 'destroy'
# on_crash = 'destroy'
#on_poweroff = 'destroy'
#on_reboot = 'restart'
#on_crash = 'restart'
#-----------------------------------------------------------------------------
# Configure PVSCSI devices:
#
#vscsi=[ 'PDEV, VDEV' ]
#
# PDEV gives physical SCSI device to be attached to specified guest
# domain by one of the following identifier format.
# - XX:XX:XX:XX (4-tuples with decimal notation which shows
# "host:channel:target:lun")
# - /dev/sdxx or sdx
# - /dev/stxx or stx
# - /dev/sgxx or sgx
# - result of 'scsi_id -gu -s'.
# ex. # scsi_id -gu -s /block/sdb
# 36000b5d0006a0000006a0257004c0000
#
# VDEV gives virtual SCSI device by 4-tuples (XX:XX:XX:XX) as
# which the specified guest domain recognize.
#
#vscsi = [ '/dev/sdx, 0:0:0:0' ]
#============================================================================
#on_crash = 'reboot'
4、配置网卡为桥接模式
[root@logicserver xen]# cd /etc/sysconfig/network-scripts/
[root@logicserver network-scripts]# cp ifcfg-eth0 ifcfg-br0
[root@logicserver network-scripts]# vim ifcfg-br0
DEVICE="br0"
BOOTPROTO="none"
NM_CONTROLLED="no"
ONBOOT="yes"
TYPE="Bridge"
IPADDR=10.1.2.180
GATEWAY=10.1.2.254
NETMASK=255.255.255.0
[root@logicserver network-scripts]# vim ifcfg-eth0
DEVICE="eth0"
BOOTPROTO="none"
HWADDR="44:8A:5B:59:F9:C0"
NM_CONTROLLED="no"
ONBOOT="yes"
TYPE="Ethernet"
BRIDGE=br0
UUID="6edaf36c-d0f4-4e54-a88a-717f589b91c6"
启动stp
[root@logicserver ~]# brctl stp br0 on
[root@logicserver ~]# brctl show
bridge name bridge id STP enabled interfaces
br0 8000.549f351d8f36 yes em1
5、在本地主机下挂cento6.5镜像文件,同时安装httpd
[root@logicserver ~]# yum install httpd -y
[root@logicserver~]# mkdir /var/www/html/tree
[root@logicserver~]# mount -o loop/data/CentOS-6.5-x86_64-bin-DVD1.iso /var/www/html/tree/
[root@logicserver ~]# service httpd restart
[root@hadoop3 ~]# df -lh
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 3.9G 3.9G 0 100% /
tmpfs 346M 0 346M 0% /dev/shm
/dev/sda1 194M 29M 155M 16% /boot
/dev/sda5 3.9G 72M 3.6G 2% /home
/dev/sda6 3.9G 72M 3.6G 2% /tmp
/dev/sda2 6.8G 2.9G 3.6G 46% /usr
/dev/sda7 2.9G 267M 2.5G 10% /var
/root/data/CentOS-6.5-x86_64-bin-DVD1.iso 4.2G 4.2G 0 100% /var/www/html/tree
[root@hadoop3 ~]# cd /root/data/
[root@hadoop3 data]# ll
总用量 3312568
-rw-r--r-- 1 root root 3392065536 9月 9 11:53 CentOS-6.5-x86_64-bin-DVD1.iso
[root@hadoop3 data]# cd /var/www/html/tree
[root@hadoop3 tree]# ll
总用量 682
-r--r--r-- 2 root root 14 11月 29 2013 CentOS_BuildTag
dr-xr-xr-x 3 root root 2048 11月 29 2013 EFI
-r--r--r-- 2 root root 212 11月 28 2013 EULA
-r--r--r-- 2 root root 18009 11月 28 2013 GPL
dr-xr-xr-x 3 root root 2048 11月 29 2013 p_w_picpaths
dr-xr-xr-x 2 root root 2048 11月 29 2013 isolinux
dr-xr-xr-x 2 root root 655360 11月 29 2013 Packages
-r--r--r-- 2 root root 1354 11月 28 2013 RELEASE-NOTES-en-US.html
dr-xr-xr-x 2 root root 4096 11月 29 2013 repodata
-r--r--r-- 2 root root 1706 11月 28 2013 RPM-GPG-KEY-CentOS-6
-r--r--r-- 2 root root 1730 11月 28 2013 RPM-GPG-KEY-CentOS-Debug-6
-r--r--r-- 2 root root 1730 11月 28 2013 RPM-GPG-KEY-CentOS-Security-6
-r--r--r-- 2 root root 1734 11月 28 2013 RPM-GPG-KEY-
6、用xm创建虚拟机
输入从另一台主机URL地址：http://10.1.2.180/tree/
[root@logicserver xen]# xm create -c centos6
┌────────────────────────┤ URL Setup ├───────│─────────────────┐ │ │ Please enter the URL containing the CentOS │
│ installation p_w_picpath on your server. │ │ │
│http://10.1.2.180/tree/______________________________________ │
│ │
│ [ ] Enable HTTP proxy │────│. │
│ Proxy URL ___________________________________ │
│ Username _______________ │ │ │────│ Password.────_______________.┘ │ │ │
│ ┌────┐ ┌──────┐│ │ │ OK │ │ Back │ │ │ └────┘ └──────┘│ │ │────│─────────┘ │
└──────────────────────────────────────────────────────────────┘<F12> next screen
Welcome to CentOS for x86_64
────
┌───────────┤ Error ├─────────── │ │
│ Unable to retrieve │ │ http://10.1.2.190/tree//p_w_picpaths │ │ /install.img. │
│ │
│ ┌────┐ │ │ │ OK │ │ │ └────┘ │ │.───────────────.│.───┘
│ │ └────────────────────────────────┘│ ────
───────────────────────────┘<F12> next screen
7、创建完成后，一定会出reboot，按ENTER键，然后会自动"destroy"
，在重新连接centos6前，先去/etc/xen/centos6，修改以下选项
#kernel = "/root/vmlinux/vmlinuz"
#ramdisk="/root/vmlinux/initrd.img" 注释添加
bootloader = "/usr/bin/pygrub"
on_reboot = 'restart'
on_crash = 'destroy
8、连接centos
[root@logicserver xen]# xm create centos6
WARNING: xend/xm is deprecated.
Using config file "./centos6".
Started domain centos6 (id=11)
[root@logicserver xen]# xm list
WARNING: xend/xm is deprecated.
Name ID Mem VCPUs State Time(s)
Domain-0 0 1021 2 r----- 1177.6
centos6 11 1024 2 r----- 4.3
进入centos6虚拟机了
[root@logicserver xen]# xm console centos6
WARNING: xend/xm is deprecated.
[root@localhost ~]# df
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/mapper/VolGroup-lv_root 8563152 752220 7375940 10% /
tmpfs 508060 0 508060 0% /dev/shm
/dev/xvda1 495844 33477 436767 8% /boot
四、添加一块硬盘
1、
给centos6添加一块硬盘xvdb
[root@logicserver vm3]# xm list
WARNING: xend/xm is deprecated.
Name ID Mem VCPUs State Time(s)
Domain-0 0 1021 2 r----- 1773.5
centos6 1 1024 2 -b---- 32.5
centos601 5 512 2 -b---- 31.7
[root@logicserver vm3]# qemu-img create -f qcow2 -o size=20G /xen/vm1/test.qcow2
[root@logicserver vm3]# xm block-list centos6
WARNING: xend/xm is deprecated.
Vdev BE handle state evt-ch ring-ref BE-path
51712 0 0 4 13 8 /local/domain/0/backend/vbd/1/51712
[root@logicserver vm3]# xm block-attach centos6 file:/xen/vm1/test.qcow2 xvdb w
WARNING: xend/xm is deprecated.
[root@logicserver vm3]# xm block-list centos6
WARNING: xend/xm is deprecated.
Vdev BE handle state evt-ch ring-ref BE-path
51712 0 0 4 13 8 /local/domain/0/backend/vbd/1/51712
51728 0 0 4 15 902 /local/domain/0/backend/vbd/1/51728
进到cento6下，查看会多出一块硬盘
[root@localhost ~]# fdisk -l
Disk /dev/xvda: 10.5 GB, 10485760000 bytes
255 heads, 63 sectors/track, 1274 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x000db375
Device Boot Start End Blocks Id System
/dev/xvda1 * 1 64 512000 83 Linux
Partition 1 does not end on cylinder boundary.
/dev/xvda2 64 1275 9726976 8e Linux LVM
Disk /dev/mapper/VolGroup-lv_root: 8908 MB, 8908701696 bytes
255 heads, 63 sectors/track, 1083 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/mapper/VolGroup-lv_swap: 1048 MB, 1048576000 bytes
255 heads, 63 sectors/track, 127 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Disk /dev/xvdb: 0 MB, 197120 bytes
255 heads, 63 sectors/track, 0 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
2、移除硬盘
[root@logicserver vm3]# xm block-detach centos6 51728
3、添加网卡，由于只有一个桥br0
root@logicserver ~]# xm network-attach
WARNING: xend/xm is deprecated.
Error: 'xm network-attach' requires between 1 and 11 arguments.
Usage: xm network-attach <Domain> [type=<type>] [mac=<mac>] [bridge=<bridge>] [ip=<ip>] [script=<script>] [backend=<BackDomain>] [vifname=<name>] [rate=<rate>] [model=<model>][accel=<accel>]
[root@logicserver ~]# xm network-attach centos6 bridge=br0
[root@logicserver ~]# xm network-list centos6
WARNING: xend/xm is deprecated.
Idx BE MAC Addr. handle state evt-ch tx-/rx-ring-ref BE-path
0 0 00:16:3e:47:ec:15 0 4 14 768 /769 /local/domain/0/backend/vif/1/0
1 0 00:16:3e:6b:b4:d5 1 4 15 1280 /1281 /local/domain/0
到centos6下去查看，多了一个eth1
root@centos6 ~]# ifconfig -a
eth0 Link encap:Ethernet HWaddr 00:16:3E:47:EC:15
inet addr:10.1.2.181 Bcast:10.1.2.255 Mask:255.255.255.0
inet6 addr: fe80::216:3eff:fe47:ec15/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:106273 errors:0 dropped:0 overruns:0 frame:0
TX packets:14782 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:47692920 (45.4 MiB) TX bytes:1088040 (1.0 MiB)
Interrupt:18
eth1 Link encap:Ethernet HWaddr 00:16:3E:6B:B4:D5
BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
Interrupt:17
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)
移除网卡
[root@logicserver ~]# xm network-detach centos6 1
转载于:https://blog.51cto.com/zouqingyun/1693339
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